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Dry ice and pH

I have to admit that the colour change was not a pronounced as I was hoping for with carbon dioxide dissolving to form carbonic acid. In the past I have used other pH indicators which give a much bigger colour change. This is due to the relative high pKa of carbonic acid ~ 6 in contrast to acetic acid in vinegar (pKa ~ 4).
I’m keen to repeat this using a different indicator and possibly just blowing into a solution using exhaled carbon dioxide to change the pH.
This is a very important demonstration as it simply shows the effect that our carbon dioxide emissions have on the pH of the ocean. Acidification of the oceans is a topic that has not really been raised in the climate change debate but a very serious problem that is looming...



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